已解决：spark代码中sqlContext.createDataframe空指针异常

这段代码是使用local模式运行spark代码。但是在获取了spark.sqlContext之后，用sqlContext将rdd算子转换为Dataframe的时候报错空指针异常

java 复制代码

Exception in thread "main" org.apache.spark.sql.AnalysisException: java.lang.RuntimeException: java.lang.NullPointerException;
	at org.apache.spark.sql.hive.HiveExternalCatalog.withClient(HiveExternalCatalog.scala:106)
	at org.apache.spark.sql.hive.HiveExternalCatalog.databaseExists(HiveExternalCatalog.scala:194)
	at org.apache.spark.sql.internal.SharedState.externalCatalog$lzycompute(SharedState.scala:114)
	at org.apache.spark.sql.internal.SharedState.externalCatalog(SharedState.scala:102)
	at org.apache.spark.sql.hive.HiveSessionStateBuilder.externalCatalog(HiveSessionStateBuilder.scala:39)
	at org.apache.spark.sql.hive.HiveSessionStateBuilder.catalog$lzycompute(HiveSessionStateBuilder.scala:54)
	at org.apache.spark.sql.hive.HiveSessionStateBuilder.catalog(HiveSessionStateBuilder.scala:52)
	at org.apache.spark.sql.hive.HiveSessionStateBuilder$$anon$1.<init>(HiveSessionStateBuilder.scala:69)
	at org.apache.spark.sql.hive.HiveSessionStateBuilder.analyzer(HiveSessionStateBuilder.scala:69)
	at org.apache.spark.sql.internal.BaseSessionStateBuilder$$anonfun$build$2.apply(BaseSessionStateBuilder.scala:293)
	at org.apache.spark.sql.internal.BaseSessionStateBuilder$$anonfun$build$2.apply(BaseSessionStateBuilder.scala:293)
	at org.apache.spark.sql.internal.SessionState.analyzer$lzycompute(SessionState.scala:79)
	at org.apache.spark.sql.internal.SessionState.analyzer(SessionState.scala:79)
	at org.apache.spark.sql.execution.QueryExecution.analyzed$lzycompute(QueryExecution.scala:57)
	at org.apache.spark.sql.execution.QueryExecution.analyzed(QueryExecution.scala:55)
	at org.apache.spark.sql.execution.QueryExecution.assertAnalyzed(QueryExecution.scala:47)
	at org.apache.spark.sql.Dataset$.ofRows(Dataset.scala:74)
	at org.apache.spark.sql.SparkSession.createDataFrame(SparkSession.scala:300)
	at org.apache.spark.sql.SQLContext.createDataFrame(SQLContext.scala:272)
	at cn.itcast.xc.dimen.AreaDimInsert$.main(AreaDimInsert.scala:39)
	at cn.itcast.xc.dimen.AreaDimInsert.main(AreaDimInsert.scala)
Caused by: java.lang.RuntimeException: java.lang.NullPointerException
	at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:522)
	at org.apache.spark.sql.hive.client.HiveClientImpl.newState(HiveClientImpl.scala:180)
	at org.apache.spark.sql.hive.client.HiveClientImpl.<init>(HiveClientImpl.scala:114)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at org.apache.spark.sql.hive.client.IsolatedClientLoader.createClient(IsolatedClientLoader.scala:264)
	at org.apache.spark.sql.hive.HiveUtils$.newClientForMetadata(HiveUtils.scala:385)
	at org.apache.spark.sql.hive.HiveUtils$.newClientForMetadata(HiveUtils.scala:287)
	at org.apache.spark.sql.hive.HiveExternalCatalog.client$lzycompute(HiveExternalCatalog.scala:66)
	at org.apache.spark.sql.hive.HiveExternalCatalog.client(HiveExternalCatalog.scala:65)
	at org.apache.spark.sql.hive.HiveExternalCatalog$$anonfun$databaseExists$1.apply$mcZ$sp(HiveExternalCatalog.scala:195)
	at org.apache.spark.sql.hive.HiveExternalCatalog$$anonfun$databaseExists$1.apply(HiveExternalCatalog.scala:195)
	at org.apache.spark.sql.hive.HiveExternalCatalog$$anonfun$databaseExists$1.apply(HiveExternalCatalog.scala:195)
	at org.apache.spark.sql.hive.HiveExternalCatalog.withClient(HiveExternalCatalog.scala:97)
	... 20 more
Caused by: java.lang.NullPointerException
	at java.lang.ProcessBuilder.start(ProcessBuilder.java:1012)
	at org.apache.hadoop.util.Shell.runCommand(Shell.java:482)
	at org.apache.hadoop.util.Shell.run(Shell.java:455)
	at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:715)
	at org.apache.hadoop.util.Shell.execCommand(Shell.java:808)
	at org.apache.hadoop.util.Shell.execCommand(Shell.java:791)
	at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:656)
	at org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:444)
	at org.apache.hadoop.fs.FilterFileSystem.mkdirs(FilterFileSystem.java:293)
	at org.apache.hadoop.hive.ql.session.SessionState.createPath(SessionState.java:639)
	at org.apache.hadoop.hive.ql.session.SessionState.createSessionDirs(SessionState.java:567)
	at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:508)
	... 35 more

sqlContext不为空指针，area也不为空指针，这个错的排查还是比较难的。

经发现，是本地模式下，如果在windows环境下运行该代码，并且windows没有配置HADOOP_HOME环境变量就会报这个错

这里直接给出解决方案
情况1：⽆hadoop环境
先准备好winutils
下载地址：
链接：https://pan.baidu.com/s/17Oy_CHoHBFYGk3-fCo8bJw
提取码：jco5

将这个路径配置成HADOOP_HOME的环境变量

重启idea，再次运行代码，即可解决上述问题
情况2：有hadoop环境
确认HADOOP_HOME环境变量已正确配置
把winutils.exe复制到HADOOP_HOME⽬录内bin⽬录下，如下图所示：
环境变量配置：

⽬录结构：